Should two more divergent methods exist of organizing a bass clarinetdouble bass interaction, then theyre probably not terrestrial.

Utilizing electronic processing in some way on the four tracks of their CD, Icelandic bassist Skúli Sverrisson and Australian clarinetist Anthony Burr seem intent on burying the customary textures of their instruments. In contrast, bassist Bruno Chevillion and clarinetist Jean-Marc Foltz, both French, intensify the wood, string and metal construction of their chosen implements to emphasize tones, unaltered with adds-ons.

Perhaps the sounds on A Thousand Incidents Arise should most properly be dubbed ambient-electronic, while those on Cette Opacité, called acoustic invention. Recorded in concert at a Strasbourg jazz festival, the concordance exhibited on the second disc, relates more to a shared vision than co-nationalism. While making an exact comparison between the duos may be akin to similarly evaluating a French poodle and a koala bear, Sverrissons and Burrs linkage appears weakened by an overflow of mutated electronics.

Studio-bound, the bass-like qualities of Sverrissons instrument almost vanish on sections of the CDs tracks, replaced with unidentifiable, minutely shifting timbres and extended periods of stasis. Along with reduced pitchsliding and micro tone-layering, droning washes of organ-like tones seep into every part of the compositions. At best, the result is mesmerizing; at worse sleep-inducing.

Waves of ambient glissandi attain such overpowering proportions in fact, that it almost seems as if theyre spreading all over the soundfield, the way water breached the levees around the New Orleans and enveloped the lands below sea level. Oddly enough, as someone whose experience has included collaboration with semi-minimalists such as contemporary composers Alvin Lucier, John Zorn and La Monte Young, its surprising that these efforts come not from Brisbane-native Burr, but from Reykjaviks Sverrisson, who most often works with post-fusion improvisers like Americans, reedist Chris Speed and drummer Jim Black.

When Sverrisson finally exposes a recognizable double bass tone on Except in Memory  the final track  the lower-pitched flanged chords nonetheless appear in a soup of undulating, outwardly radiating textures  perhaps also triggered by the bass man. Burrs irregularly vibrated contributions protrude from the mix like raisins in a serving of porridge.

These slender reed-biting flutters and vibrations also shape Change is Far More Radical than We Are at First Inclined to Suppose, the discs verbosely-titled, almost 16½-minute, centrepiece. Somehow the near-static and largo reverb  perhaps processed by Sverrissons effects pedal  solidify into near-ecclesiastical, layered harmonies. On top of this appear Burrs woody portamento textures, overblowing and pitchsliding in such a way that the largo modes are opaque, yet translucent enough to let individual possibilities assert themselves.

Ironically, its Cette Opacités all-acoustic set whose title loosely translates as this opaqueness. Yet any murk Foltz and Chevillion create is as transparent as glass when compared to A Thousand Incidents Arise. That may be because the two rather than identifying with contemporary so-called serious music like Burr or a version of fusion like Sverrisson, are primarily jazzers, with only Foltz, dipping his toes into New music. Even so one of those outlets is as part of Le Trio de Clarinettes, the other member of whom  Sylvain Kassap and Armand Angster  also have improv credentials. Besides that, Foltz plays in many bands with Chevillon, most notably pianist Stéphan Olivas combo. Avignon-native Chevillon is first-call bassist for top improvisers in France clarinetist Louis Sclavis and guitarist Marc Ducret, to name two  and from overseas  such as American drummer Paul Motian.

Concerned with expanding the technical limitations of the bull fiddle on this CD, he and Foltz participate in nine string-reed jousts that vibrate sonics either against or in concordance with one another. In the midst of the bassist resonating sweeping spiccato lines and jetes, the clarinetist responds with snorts, whoops and echoes from his oral cavity that buzz with lip and tongue motion. Sometimes legato and zart the two instruments gorgeous harmonies sound almost traditionally impressionistic. Other times the two explode into shrill aviary quivers that only latterly segment into polyphonic vibrations.

Without electronics, undulating waveforms are still evident, as they unfold often linking Foltzs experiments in circular breathing with Chevillons underplayed string plasticity or percussive raps on his axes ribs and belly. Sometimes the color field is organized in a pointillistic fashion, other times with expansive strokes.

Two tracks are particularly memorable. Entre faire et entendre has Foltz on straight clarinet and Chevillon pulsing complementary bass tones as if the two were King of Swing clarinetist Benny Goodman and bassist Arvell Shaw playing with a contemporary sheen. Adopting a proper pre-modern tone, the reed man fluidly sputters so as to match the bassists double-stopped and slapped bass lines. Midway through, textures reach a polyphonic crescendo  then divide  as Foltzs high-pitched portamento settles across frailing, single-note bass plucks, and reappear for a final coda of minimal clarinet breaths.

On the other hand, the almost nine minutes of This imbalance and its consequences redirects Foltzs echoing and choked reed-biting with col legno jetes that are as authoritative as they are resonating. Moving contrapuntally towards the finale, Chevillon exposes the double-stopping buzzing textures of the strings and Foltz a harsh, overblown irregular vibration that insect with the bull fiddles output like attached pieces of a jigsaw puzzle.

Both Burr and Sverrisson and Foltz and Chevillon are extending bass-reed literature, but only the later two do so without extraneous textures.